Kotlin read file with File.useLines

File.useLines() reads all data as a list of lines and provides it to the callback. It closes the reader in the end.

Kotlin read a file with File.useLines

The example reads a file and prints it to the console. We add line numbers to the output.
import java.io.File
 
fun main(args: Array<String>) {
    
    val fileName = "src/resources/sample.txt"
    
    val myList = mutableListOf<String>()

    File(fileName).useLines { lines -> myList.addAll(lines) }
    
    myList.forEachIndexed { i, line -> println("${i}: " + line) }
}
A mutable list is created:
val myList = mutableListOf<String>()
With File.useLines() we copy the list of the lines into the above created mutable list:
File(fileName).useLines { lines -> myList.addAll(lines) }
With forEachIndexed() we add a line number to each line:
myList.forEachIndexed { i, line -> println("${i}: " + line) }


Related C Programs with Output and Step-By-Step Explanation:

Kotlin- Create Class Example Kotlin - for Loop Examples Kotlin - while and do-while loop example Kotlin - if statement example Kotlin - Nested if Statement Example Kotlin - if-else Statement Example Kotlin - if-else-if Statement Example Kotlin - when Expression Example Kotlin - break and continue Keyword Example Kotlin - Nested Class Example Kotlin - Inner Class Example Kotlin - Inheritance Example Kotlin - Abstract Class Example Kotlin Interface Example Kotlin Interfaces Inheritance Example Kotlin - Enum Class Example Kotlin - Enum Class Implementing Interfaces Example kotlin - Data Class Example Kotlin - Array Initialization Example Kotlin Array Basic Operations Kotlin - Sorting Arrays Example Kotlin - Two-Dimensional Arrays Example Kotlin - Find Array Elements Example Kotlin array initialization example Kotlin array basic operations Kotlin array count example Kotlin array traversal example Kotlin filtering arrays example Sorting arrays in Kotlin example Kotlin String Looping Example Kotlin Remove Leading and Trailing Whitespaces Example Kotlin Remove All Whitespaces from a String Example Kotlin Empty/Blank String Example Kotlin String Case Example Kotlin Comparing Strings Example Kotlin String Interpolation Example Kotlin - Get First and Last Characters of a String Example Kotlin String Example Kotlin List drop Example Kotlin List all Example Kotlin List any Example Kotlin List filter Example Kotlin List slice() Example Kotlin List contains() Example Kotlin List Sort Example - Ascending and Descending Order Kotlin List Iterate Example - forEach(), for Loop, forEachIndexed() and ListIterator Kotlin List first and last Element Example Kotlin List Count Example Kotlin List Indexing Example Kotlin List Example Kotlin listOf() Example Kotlin Set all Example Kotlin Set any Example Kotlin Set filter Example Kotlin Set union Example Kotlin mutableSetOf() Example Kotlin Set contains Example Kotlin Set Sort Example - Ascending and Descending Order Kotlin Set Iterate Example - forEach(), for Loop, forEachIndexed() and Iterator Kotlin Set first and last Element Example Kotlin Set count Example Kotlin Set indexing Example Kotlin Set Example Kotlin setOf() Example Stack Implementation in Kotlin Queue Implementation in Kotlin Deque Implementation in Kotlin Singly Linked List Implementation in Kotlin Doubly Linked List Implementation in Kotlin Circular Linked List Implementation in Kotlin Bubble Sort Algorithm in Kotlin Heap Sort Algorithm in Kotlin Insertion Sort Algorithm in Kotlin Merge Sort Algorithm in Kotlin Quick Sort Algorithm in Kotlin Selection Sort Algorithm in Kotlin

Comments

Post a Comment